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United States Patent | 5,175,085 |
Johnson ,   et al. | December 29, 1992 |
Disclosed are compositions and methods for diagnosing autoimmune insulin dependent diabetes mellitus. In general, diagnostic methods of the invention include testing for the presence of an autoimmune immunoglobulin in a suspected patient's serum wherein the immunoglobulin is identified by its ability to interfere with the glucose transporting activity of a pancreatic islet cell glucose transporter. The inventors have discovered that the presence of such an autoimmune antibody in patient's serum is diagnostic of autoimmune insulin dependent diabetes mellitus. In particular aspects the diagnostic assay of the invention involves the incubation of isolated and dispersed islet cells, such as rat islet cells, in the presence of immunoglobulin obtained from the patient. Following such an incubation, the islet cells are tested for their ability to uptake glucose. A diagnosis is made through a determination that immunoglobulins in the serum of the patient specifically inhibit the uptake of glucose by the islet cells.
Inventors: | Johnson; John H. (Dallas, TX); Unger; Roger H. (Dallas, TX) |
Assignee: | Board of Regents, The University of Texas System (Austin, TX) |
Appl. No.: | 483224 |
Filed: | February 20, 1990 |
Current U.S. Class: | 435/7.21; 435/7.8; 436/506; 436/811 |
Intern'l Class: | G01N 033/567 |
Field of Search: | 435/7.21,7.8 436/506,811 |
Foreign Patent Documents | |||
0334687 | Jun., 1989 | EP. | |
0383129 | Jul., 1990 | EP. |
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TABLE 1 ______________________________________ Characteristics of Diabetic Patients and Normal Subjects Age Islet Cell Antibody Patient Sex (years) (cytoplasmic) ______________________________________ Type 1 1 M 19 + 2 M 7 + 3 M 13 + 4 M 10 + 5 F 8 + 6 F 7 + 7 F 11 + 8 F 8 + 9 F 7 + 10 F 8 + 11 M 12 + 12 M 14 + 13 F 24 + 14 M 6 +/- 15 M 11 +/- 16 F 7 - 17 F 11 - 18 F 11 - 19 F 13 - 20 M 9 - 21 F 12 - 22 M 19 - 23 F 8 - 24 F 12 - 25 M 6 - 26 M 34 - 27 F 27 - ______________________________________ Mean Values .+-. IDDM Patients 12M/15F 12.4 .+-. 6.8 (N = 27) NIDDM Patients 3M/2F 57.0 .+-. 5.6 (N = 5) Normal Subjects 18M/10F 35.8 .+-. 10.3 All type 1 patients were treated with NPH insulin. The diagnosis of NIDDM diabetes in patients #26 and 27, the two oldest patients was based on a history of ketoacidosis. Three of the NIDDM patients were receiving gliburide and were receiving NPH insulin.